Improvement in curtain-fixtures



N. CAMPBELL.

v CURTAIN FIXTURES.

3 13o,109 'Patentd July 25,1876.

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rum-ans, PMOTO-UTHQGRAPDQER, WASHINGTON, D c.

rrED STATES PATENT QFFIGET.

NATHAN CAMPBELL, OF ROCHESTER, NEW YORK.

IMPROVEMENT IN'CURTAIN-FIXTURES.

Specification forming part oi Letters Patent No. 180, [09, dated July25, 1876; application filed 7 December 22, 1875. I

To all whom it may concern:

Be it known that I, NATHAN CAMPBELL, of the city of Rochester, in thecounty of Monroe and State of New York, have invented a certain new anduseful Improvement in Curtain-Fixtures; and I do hereby declare that thefollowing is a full, clear, and exact description of the constructionand operation of the same, reference being bad to the accompanyingdrawings, in which- Figure 1 is a front elevation, showing myimprovement applied to a window. Fig. 2 is a side elevation of thefixture. Fig. 3 is a perspective view, showing the par-ts'separated.Fig. 4 is a diagram, showing the operation of the ratchet and pawl.

My improvement relates to curtain-fixtures in which a ratchet andpawl-lever are used to control the running down of the curtain by thedrawing of a cord which releases the pawl from the ratchet.

The invention consists in the peculiar construction of the ratchet andlever, as hereinafter described. I

A represents the bracket or fixture, which is attached to the casing tosupport the parts. B is the lever, and O is the ratchet. The ratch-' etis of peculiar shape, being in the form of a square, with fourright-angled sides, a a co, with projections at the corners, which formthe ratchet-teeth b1) 1) b. These teeth, on the inner edge, are hookedor notched under, as shown at 0 c c c. The ratchet is attached to theend of the curtain-roller, and its journal rests in the bearing d of thebracket, as usual.

Heretofore, so far as I am aware, the ratchet has been made in theordinary form of a ratchet-wheel, with rounded or curved edges, overwhich the pawl f has to ride in the running down of the curtain. Underrapid motion of the curtain in running-down, the point of the pawl, instriking on the edge to stop the 1notion, runs so high that it isfrequently thrown over or past the ratchet tooth, and fails to engage,thus causing jumping and uncertain engagement of the pawl with thetooth. This effect is aggravated by the form of the tooth itself, whichis usually square on the edge, or struck toward the center of theratchet. The action of the ordinary ratchet in use for this purpose isso irregular and uncertain from this cause that much difficulty has beenexperienced, and the motion of the curtain must necessarily be-very slowto prevent jumping.

By the construction of the ratchet of the form I have above describedthese difficulties are obviated; for at the moment of engagement thepawl strikes low upon the square edge a, and rides downward under theweight of the lever till the center of the edge is reached, when itcommences to ride upward again, under the leverage of the ratchet inmoving forward. At the end of its movement it strikes under the hook atc, and is held firmly in engagement without possibility of slippingover, as a lock is thereby produced which requires a reverse or backwardmovement of the ratchet to release it. This action of the ratchet andpawl is illustrated most clearly in Fig. 4, in which the edge of thepawl is shown as commencing to rise upon the square edge of the ratchetas the latter revolves.

By the means above described the roller can be let down rapidly, and thepawl will be sure of its engagement with the ratchet. This form of theratchet is easily drawn in molding, by making the division in the flaskangularly from one corner to the other, and removing the cast with onetooth upward.

The lever B is attached to the bracket between its foot and theroller-bearing, either by a riveted or a loose joint, as shown at g. Thepawlfis cast upon its inner side, being -made sharp-edged on the workingside, so as to strike fully into and under the notches c of the ratchet.is carried beyond the ratchet U, and has a shield, h, which houses theratchet, and the lower end is then turned inward and downward, formingthe arm 70, through which passes the cord 1. The inner side of the leveralso has a projection, m, forming a stop, which, in the outward movementof the lever, strikes the bearing d of the bracket, and prevents thelever being thrown out too far.

The lever thus constructed has its pivotjoint between the foot of thebracket, and the roller-bearing is carried outside of and beyond theratchet, and its arm 70 is also carried The outer portion of the leverdown outside, instead of between the ratchet and foot of the bracket, ashas heretofore been done. This allows free action of the lever, also aneasy disconnection at any time; and, furthermore, the extension outwardgives the necessary coun ter-weight to keep the lever in place withoutadding metal for the purpose. The stem m also serves an importantpurpose as a stop.

I am aware that levers having a shield'are known; such is shown in anapplication for a patent which I now have pending; but in such cases thearm of the lever passes between the ratchet-bearing and foot of thebracket, and not outside, as I have above described and such are notelongated, and have no stop m.

Having thus described my invention, I do not claim, broadly, either aratchet or lever; but

What I claim as new is-- 1. The ratchet G, constructed with four plainsides, a a a a, and hooked teeth I) b b b, in combination with the leverB, operating in the manner and for the purpose specified.

2. The elongated lever B, constructed with Witnesses:

R. F. ()SGOOD, E. B. Soo'r'r.

